| Primary Identifier | IPR005935 | Type | Family |
| Short Name | Mev_decarb |
| description | This group of enzymes belongs to the GHMP kinase domain superfamily. GHMP kinases are a unique class of ATP-dependent enzymes (the abbreviation of which refers to the original members: galactokinase, homoserine kinase, mevalonate kinase, and phosphomevalonate kinase) []. Enzymes belonging to this superfamily contain three well-conserved motifs, the second of which has the typical sequence Pro-X-X-X-Gly-Leu-X-Ser-Ser-Ala and is involved in ATP binding[]. The phosphate binding loop in GHMP kinases is distinct from the classical P-loops found in many ATP/GTP binding proteins. The bound ADP molecule adopts a rare syn conformation and is in the opposite orientation from those bound to the P-loop-containing proteins []. GHMP kinases display a distinctly bilobal appearance with their N-terminal subdomains dominated by a mixed β-sheet flanked on one side by α-helices and their C-terminal subdomains containing a four stranded anti-parallel β-sheet [, , , ]. Diphosphomevalonate decarboxylase (mevalonate pyrophosphate decarboxylase, () catalyzes the decarboxylation of mevalonate pyrophosphate to isopentyl pyrophosphate (IPP) [], the last step in the synthesis of IPP in the mevalonate pathway. In archaea, an alternate pathway involves decarboxylation of mevalonate monophosphate instead of diphosphomevalonate []. Mevalonate is a key intermediate in the biosynthesis of sterols and non-sterol isoprenes in the mevalonate pathway. In mammals, the majority of mevalonate is converted into cholesterol.ATP + (R)-5-diphosphomevalonate = ADP + phosphate + isopentenyl diphosphate + CO2 The classical mevalonate (MVA) pathway involves decarboxylation of mevalonate diphosphate, while an alternate pathway involves decarboxylation of mevalonate monophosphate. The enzyme responsible is known as phosphomevalonate decarboxylase []. |
